Structured light vs. laser 3D scanners – a technology comparison

3D scanners are especially useful in 3D modeling and design for users from various industries.  The device facilitates the digital 3D design of physical objects, helping to easily and quickly obtain a number of information on the dimensions, geometry or color of the modeled element.

During the 3D scanning process, thanks to structural light or laser beam, the data is collected. Then, these are reconstructed to build a file consisting of a point cloud, most often in STL format. Nevertheless, there is a possibility to save it as an OBJ, ASC or PLY extension file. The accuracy of generated data can reach up to 0.005 mm. 

The variety of appliances offered by producers is wide. The fundamental difference is the type of light used for collection of model data. 3D scanning can be performed using various technologies, e.g. laser or structured light. The type of method used is closely related to the possibilities of using the device for modeling various objects. 3D scanners can scan small, medium (e.g. car doors) or large (buildings) dimensions.

What are the main differences between laser 3D scanners and structured light 3D scanners? 

Structural light technology

3D scanners using structural light for operation emit light in the form of lines, which fall at analysed physical object. The position of the beam changes during the scan, gathering data about the object. Cameras mounted into the device register and analyse the position of the lines, generating the digital 3D model of the object. 

This type of technology is characterized by high speed of 3D scanning, which is the reason why it is dedicated to generating 3D scans of people. Structured light 3D scanners are lightweight and they are cheaper than laser 3D scanners. However, they are very sensitive to the lighting conditions. Any shadow falling at the object, has a reflection on the generated digital model. Therefore, using this type of scanner outdoors or in difficult conditions (e.g. rooms with high dustiness) may be problematic. Additionally, black or glossy surfaces must be covered with a special spray before 3D scanning begins.

Laser technology 

Laser technology, used in 3D scanners, consists in analyzing the refraction of laser rays on the surface of the tested object, or measuring the distance between a physical element and the device. The sensor or camera processes the obtained data and recreates the geometry of the object.

Laser 3D scanners are characterized by much higher precision and resolution of 3D scans, compared to devices using structured light technology. They are capable of scanning in low light conditions as well as black, shiny and white elements without the need to coat them with matting spray. Additionally, laser 3D scanners can scan large objects (e.g. buildings). They are usually more expensive than structured light scanners, and at the same time have a lower scanning speed.

Choosing the right 3D scanner is a tough business. In order to avoid tiresome covering of the elements with the matting spray, we should focus on a laser 3D scanner. In case of scanning large and middle sized objects it will also be a right choice. However, if the scanned elements will be rather small or there will be scanning of people performed, it is worth considering buying a structured light 3D scanner.  Choosing a 3D scanner tailored to your individual needs will save you time and money, so it is worth precisely defining your requirements and the use of the device, before making a purchase.